1. Field
This disclosure relates to an electrode assembly and a secondary battery comprising the same.
2. Description of the Related Technology
Unlike primary batteries which cannot be recharged, secondary batteries can be repeatedly charged and discharged. Low capacity batteries that use single battery cells may be used as power sources for various small portable electronic devices such as cellular phones, and camcorders. High power batteries that use tens of battery cells connected to each other in a battery pack may be used as power sources for electric scooters, and hybrid electric vehicles (HEV).
Secondary batteries may be manufactured in various shapes, including a cylinder shape, and a prismatic shape. The secondary battery may be fabricated by forming an electrode assembly having a separator as an insulator disposed between a positive electrode plate and a negative electrode, accommodating the fabricated electrode assembly and an electrolyte in a case, and installing a cap assembly having electrode terminals in the case.
A secondary battery employed to propel an automotive vehicle requires a high capacity and is gradually getting bulky, unlike the conventional low-capacity secondary battery used with a small-sized electronic device. A prismatic battery may have a difference in the heat dissipation between the inside and the outside of a cell due to an increase in the thickness, making it difficult to attain improved safety. In particular, in a high power secondary battery having a plurality of battery cells in a jelly roll configuration for use in HEV, there may be a considerable temperature difference between a central cell and a peripheral cell. In addition, when penetration or internal short circuit occurs to a prismatic battery, a temperature of the centrally positioned cell may be increased. Thus, there is high probability of thermal runaway, potentially resulting in fire or explosion.